Comment by ho_schi

I also still use my ThinkPad X220 happily with Archlinux. Contrary to the author I've built in immediately an OEM IPS-Panel and a Bluetooth 4.0 chip from the next generation. I bought it very late in production cycle because I prefer to keep the classic keyboard with the blue enter-button. The only nasty thing is the USB 3.0 Port which immediately went into sleep states, workarounds are either to connect a device at boot-up or use powertop to wake it up. It is even possible to attach HiDPI displays via DisplayPort (always better than HDMI) but you will fallback to 30 Hz and the tiny GPU will have a hard time.

  Pros:  
  * Mobile with A4/Letter form factor 
  * Powerful, with a dock it replaces a desktop computer
  * Standard size keyboard
  * IPS screen is still state-of-the art
  * Replaceable battery
  * Works very well with Linux
  * With a i7 CPU even provides USB 3.0
  Cons:
  * Modern ThinkPads provide a tighter case, especially the palm rest